How to Clean an Electrostatic Furnace Filter

It's a no-brainer to maintain your HVAC system if you use disposable fiberglass filters; all you have to do is throw the dirty one away and put the fresh one in. But if you're lucky enough to have a reusable electrostatic filter, you'll have to clean it every so often. The little bit of extra effort that you need to put in is well worth it, though, because electrostatic filters last a lifetime, improve filter performance and reduce the burden on landfills across the country.

Things You'll Need

Electrostatic filter

Vacuum cleaner

Garden hose

Dishwashing liquid soap

Water

Plastic spray bottle

Open the HVAC vent where the electrostatic furnace filter is installed. Remove the filter from its seating.

Use the wand attachment of a vacuum cleaner to suck all of the dust and dirt from both sides of the filter. If you clean your filter at least every other month, this may be all of the maintenance that is required. But if you clean it less frequently or if you want a deeper clean, proceed to the next step.

Take the vacuumed-off filter outside to hose it off. At first, spray down the filter in the opposite direction of the air flow. Spray this side of the filter extensively before switching to hose off the other side. Leave the hosed-off filter out in the sun for a few minutes to air dry. If it is clean enough for your satisfaction, skip to the last step. Otherwise, proceed to step four.

Mix a soapy solution of liquid dishwashing soap and water in a plastic spray bottle. Spray down both sides of the filter with a liberal coating of the soap, then allow it to soak for about five minutes. Rinse off the filter thoroughly with water from the hose and allow it to dry in the sun for a few minutes.

Slide the clean, dry filter back into its slot in your HVAC system and secure any latches or panels needed to hold it in place.

Tips & Warnings

If you vacuum off your filter once a month, you may never need to clean it with water or soap.

If you initially hose off your filter in the same direction as the intended air flow, you'll just wedge dust and dirt particles farther into the mesh. Always hose against the air flow first.

To maintain the structural integrity of an electrostatic filter, don't leave it out in the sun for more than ten or fifteen minutes.